GSA Medals & Awards

2007
Laurence L. Sloss Award

Presented to Michael A. Arthur

Citation by Bradley B. Sageman

As the result of a recommendation from my post doctoral advisor to be, Mike Arthur, I was invited to interview at Northwestern in 1991. Mike was well known to the department as a result of his long and productive collaboration with Northwestern faculty member Sy Schlanger, and failing in their effort to hire Mike as a replacement for Sy (Mike had already agreed to fill the department head position at Penn State), they asked him to suggest alternatives. I was thoroughly astounded when, out of the blue, they called me for an interview, and I was very grateful that Mike had recommended me. During that interview I remember Larry Sloss, the quintessential crusty emeritus, saying right before my talk that Mike was a great scientist and a good friend, and I therefore damn well better put on a good show. Larry always knew exactly how to set a person at ease.

Having had the privilege of working with Mike over the years, and of occupying an office directly across from Larry between 1992 and his death in late 1996, I know a little bit about these two great geologists. The Sloss Award was created in memory of Larry’s profound contributions to sedimentary geology and his dedicated service to GSA, and it provides us the opportunity to honor others who have made similar contributions through their careers. I can say with utter confidence that Mike Arthur is a fitting recipient of the Sloss award. His lifetime achievements in sedimentary geology uncannily exemplify Larry’s career, in terms of scientific contributions and service to GSA, but also as regards the nature and quality of his professional character.

Larry was an incisive yet broad thinker who brought vision and creativity to a field that was largely descriptive when he started working in it. He animated sedimentary geology by infusing the study of facies and stratal packages with his insightful analysis of the physical processes that produce them. He dared to think outside the box of his regional subsurface studies in Montana and extrapolate to a cratonic scale. And then he influenced a cadre of young Northwestern students who went on careers at Exxon and, well the rest is history.

Mike’s contributions have a similar flavor—he is an extremely broad geological thinker who has expanded our understanding of Earth History by animating stratigraphic and sedimentologic sections with creative analysis of the biogeochemical processes recorded in their elemental and isotopic signatures. He was one of the first geoscientists to apply stable isotopic techniques to paleoceanographic and paleoclimatic problems, and I can think of a long list of geochemical proxies that were discovered or illuminated in one Arthur manuscript or another. He is one of the most creative and empirically rigorous practitioners of the multiproxy approach for deep time paleoenvironmental analysis and he has made significant contributions to our understanding of the controls on organic carbon burial and the global carbon cycle, the expression of orbital forcing of climate in sedimentary systems, the biogeochemical cycles of sulfur, iron, nitrogen, and phosphorus, and their relationship to the redox state of the oceans and atmosphere, and many others.

Mike’s scientific contributions span the geological record from the Precambrian to the Holocene, and he is equally at home on an outcrop, a research vessel at sea, in the lab, or behind a computer, modeling geochemical processes. He has authored or co-authored over 160 peer-reviewed publications, and contributed to a series of reports for the Ocean Drilling Program. Many of the co-authors of those publications, with names like Zachos, Glenn, Pagani, and Hurtgen, attest to his skill as an advisor, and others like Dean, Scholle, Schlanger, Kump, and Bralower, speak to his strong collaborative spirit.

Mike has been equally dedicated to teaching and service—he has long offered one of the largest introductory undergraduate courses in his department, and he is teaching four sections of it this year alone! He has served his institution as department head, the scientific community as editor or co-editor of many publications, and the GSA as a councilor and a member of many committees. He has been honored by Penn State with the Wilson Award for research, and again for service to the university, and by the Society for Sedimentary Geology with the Shepard Medal. In addition, he was recently elected Fellow of the American Geophysical Union.

Like Larry Sloss, Mike has been a pioneer in many of his efforts. And like Larry, Mike has also managed to achieve without ignoring the really important things in life….like his family, his farm, his students, his colleagues, a good bottle of wine, a quiet dinner with an old friend, or strumming a fine guitar on the back porch. He has a big heart and has always been willing to give a chance to those who might not otherwise have had the opportunities he made possible. In this sense, both his career and his character remind me of Larry.

After my interview talk was over Larry paid me a great compliment, saying “at least you didn’t embarrass yourself, Sageman,” delivered with that wry grin of his. If he were here tonight I am sure his message to Mike would carry a good deal more praise. … something like “damn good show, Arthur” … and then he might say … ”now give us a nice short speech so we can all go eat.”

2007 Laurence L. Sloss Award - Response by Michael A. Arthur

I am deeply honored to receive the Laurence L. Sloss Award. I humbly thank the Sedimentary Geology Division of GSA and the various committees that undoubtedly had to make some difficult decisions this year. It is also with great affection that I thank Brad Sageman for his friendship, scientific collaboration and for his well-spun tale and citation.

In his 1980 Twenhofel Medal acceptance speech, Larry argued that success “… for me, at least, … was another case of being with the right people in the right place at the right time and that, I must presume, is why I stand here today.” I can wholeheartedly echo his sentiments there. In my view, I stand before you today because of the friends, mentors, colleagues and students that I have been so fortunate to have. And, it was not always through science alone that these folk had their major impact on me. The intrigue of black shales and pelagic carbonates for me was promoted and nurtured by my mentors Seymour O. Schlanger and Alfred G. Fischer. I also learned of the benefits and pleasures of wine and exotic foods during field excursions with both of these fine gentlemen. Al Fischer inspired a “holistic” view to my research early in my career that I have always valued. I must also acknowledge Peter A. Scholle for encouraging my fledgling efforts to apply stable isotopes to stratigraphic and paleoceanographic problems, and Erle G. Kauffman for introducing me to the wonders of epicontinental seas. And where would I be without the excellent collaboration of Walter E. Dean in all things cyclic and geochemical?

My first awareness of Larry Sloss was through my undergraduate sed/strat course, taught by Sy Schlanger, which used the venerable text by Krumbein and Sloss (1963) “Stratigraphy and Sedimentation.” Much later, I had the privilege of knowing Larry, and we even published together—alas, this was a memorial for Sy Schlanger. Sloss was, as noted, a pioneer of sequence stratigraphy. His classic paper on “Sequences in the Cratonic Interior of North America” was published in the highly respected ‑ in 1963. For those of you concerned with evaluating a colleague’s impact through quantitative means, note that Professor Sloss’ citation index is quite modest, but that one influential paper has been cited at least 375 times to date. Few papers in the geosciences have reached that level. His work led to concepts of the interplay of sea level and sedimentation that were promoted by his students, among others, and though sometimes controversial, provided vitality to sedimentary geology and garnered much interest from the hydrocarbon industry in the late 1970s and 80s. My research was certainly profoundly influenced by the resulting emphasis on variations in sea level and “global cycle charts.” Who didn’t need a global sea level curve to which everything could be correlated?

Larry’s more interpretive and controversial work, however, came later in his life, and received much less attention. The inimitable Professor Sloss, unlike many of us whom he termed “Neo-Neptunists,” was not convinced that changes in eustatic sea level produced such globally correlative sequences. In papers published just two or three years before his death at 80 years old, Sloss continued to argue that strong synchroneity of uplift or subsidence in widely separated cratonic basins as the result of changes in mantle processes was a plausible mechanism for the origin of cratonic sequences. I suspect that he would have appreciated some of the later work on numerical modeling of dynamic topography that seems to lend support to his ideas. I think that there is much more to be done in this regard. I admire the fact that Larry Sloss was still captivated by sedimentary geology and publishing thoughtful papers in his retirement as well as serving the profession he loved. Indeed, it is still, for me, fun to go to work every day, and, although I have found many other quite enjoyable things to do, when retirement comes, I cannot envision totally giving up the excitement of working on fascinating geological problems and collaborating with really great people. For my own part, I hope that, late in my career, I too am able to see through some self-created geobabble to provide more incisive analyses of the causes and consequences of oceanic anoxia or the global environmental effects of large igneous provinces.

Like Larry, I do not believe that our field is moribund. To be sure, the field of sedimentary geology is quite robust today. The application of quantitative methods to modeling sedimentary processes is in its prime. One only needs to note the ongoing development of a “community sediment model” within the NSF Margins Program as an example. Ultimately, using such physical models, we should be able to more effectively examine the linkages between uplift, climate, erosion and sediment yield for comparison to patterns observed in the stratigraphic record. We might even eventually firm up the elusive connection between eustacy and stratigraphic sequences that Larry Sloss eschewed. Likewise, the availability of geochemical proxies for quantifying environmental parameters has burgeoned over the past several decades, as has our ability to use them in high-resolution studies of global change. Our temporal resolution of events and trends has improved significantly as well, in part because of orbitally induced cyclicity and its recognition and documentation in the record.

Well-trained sedimentary geologists are, and will continue to be, in demand in applied fields, and this will fuel hiring in academia as well. In particular, sedimentary geologists will be called upon to significantly improve predictions of subsurface sedimentary characteristics for exploration and efficient extraction of oil, gas, coal and water, and even for carbon dioxide sequestration. Let us not forget, however, that most of us were lured to geology by an opportunity (we thought) to work outdoors and pushed in that direction by our curiosity regarding what stories the rocks could tell. I know I was, although I have spent far more time behind a computer or in the lab than I ever anticipated, and it is continuing curiosity about how the Earth works that keeps me involved at this stage in my career. It is my fervent hope that curiosity-based science will still garner substantial funding even while we strive to serve society through relevant research. Applied science alone cannot entrain legions of enthusiastic young scientists into our field.

Oh how I envy the wordsmithing abilities and unabashed nature of some of my geological forebearers. So, with apologies, because try as I might I could not improve on it, I will end my acceptance speech with the following words from Larry Sloss’ Twenhofel Medal acceptance which are apt today. “I wish I could leave you with some pithy aphorism, some trenchant maxim, that would make me seem a more worthy role model for rising young geologists; instead, all that runs through the mind is that a lack of virtue does not necessarily lead to a lack of rewards, that procrastination saves time (the problem may go away) and that there is, indeed, a free lunch and I just had one.” Just one thing more—help GSA serve our profession and have fun out there! Thank you for your kind attention.